Transponders are electronic devices incorporated into secure documents such as “smart cards” and “electronic passports” using RFID (radio frequency identification) technology.
The transponder (or inlay, or chip card) itself generally comprises (includes):                a substrate (or inlay substrate) which may comprise a sheet of a synthetic material or paper;        a chip (or chip module, chip unit or naked die) installed on the substrate (or in a recess in the surface of the substrate) and having terminals (or contact surfaces, or pads); and        an antenna wire (or conductor) mounted on or in the substrate, formed with “turns” as a flat (substantially planar) coil and connected (bonded) by its ends or end portions to the terminals (terminal areas) of the chip module.        
The inlay substrate may comprise one or more layers of Polyvinyl Chloride (PVC), Polycarbonate (PC), polyethylene (PE), PET (doped PE), PETE (derivative of PE), TYVEK, Teslin™, Paper or Cotton/Noil, and the like. For example, a single layer of uncoated Teslin™, with a thickness of 356 microns. In the main hereinafter, inlay substrates comprising Teslin™ or polycarbonate (PC) will be described.
Teslin™ is a synthetic printing media, manufactured by PPG Industries. Teslin™ is a waterproof synthetic material that works well with an Inkjet printer, Laser printer, or Thermal printer. Teslin™ is also single-layer, uncoated film, and extremely strong. In fact, the strength of the lamination peel of a Teslin™ sheet is 2-4 times stronger than other coated synthetic and coated papers. Teslin™ comes in the sizes of 7 mil to 18 mil, though only sizes 10 mil and 14 mil are sized at 8.5″ by 11″, for printing with most consumer printers. Also available are perforated versions of Teslin, specifically, 2up, 6up, and 8up. Teslin™ is a microporous polymer. Polycarbonate (PC) is typically used for national ID cards, and also as the material in certain passports (such as for the Datapage, in contrast to the e-Cover).
The inlay substrate may have an area designated as a “transponder site” whereat the chip module and antenna will be installed. (A recess in the inlay substrate may constitute the transponder site.) The transponder site may itself have two areas designated as “terminals areas” corresponding in position to the two terminals of the chip module which will be installed at the transponder site. (The transponder site and terminal areas are generally geometric abstractions, the chip module and terminals are physical elements.) Hence, it should be understood that, where applicable, the terms (and reference numerals for) “transponder site” and “chip module” may be used interchangeably, and that the terms “terminal areas” and “terminals” may similarly be used interchangeably.
In the main hereinafter, RFID chips incorporated into chip modules will be described. The chip module may be a leadframe-type chip module comprising an RFID chip encapsulated by a mold mass and supported by and connected to a leadframe having two terminal areas.                the mold mass may be approximately 240 μm thick and 5 mm wide        the leadframe may be approximately 80 μm thick and 8 mm wide.        
The chip module may be disposed in a recess extending into the surface of the substrate measuring for example 5.5 mm wide×8.5 mm high (generally the recess is only slightly larger than the chip module to allow some clearance during installation, while maintaining good registration).
The recess for receiving the chip module extends into the inlay substrate from a “top” surface thereof, and may be a “window” type recess extending completely through the inlay substrate to a “bottom” surface thereof, or the recess may be a “pocket” type recess extending only partially through the inlay substrate towards the bottom surface thereof.
The recess may have a “straight” profile—in other words, substantially constant cross-dimension through (or into) the inlay substrate. Or, the recess may have a “stepped” profile, including a larger cross-dimension at the top surface of the substrate than at (or towards) the bottom surface of the inlay substrate. The recess is generally sized and shaped to accommodate the size and shape of the chip module being disposed therein. The term “cavity” may be used interchangeably with “recess”. A stepped recess profile is commonly used to accommodate a leadframe module, since the leadframe is typically wider (8-10 mm) than the mold mass (4-6 mm) of the chip module.
The antenna wire can be self-bonding copper wire or partially coated self-bonding copper wire, enamel copper wire or partially coated enamel wire, silver coated copper wire, un-insulated wire, aluminum wire, doped copper wire or litz wire.
The conventional method of mounting the wire is using a sonotrode tool which vibrates, feeds the wire out of a capillary, and embeds it into the surface of the substrate. Examples of embedding a wire in a substrate, in the form of a flat coil, and an ultrasonic tool for performing the embedding (and a discussion of bonding), may be found in U.S. Pat. No. 6,698,089 (refer, for example, to FIGS. 1, 2, 4, 5, 12 and 13 of the patent). See also FIGS. 1 and 2 of U.S. Pat. No. 6,233,818. Both of these patents are incorporated by reference herein. It is also known that a coated, self-bonding wire will stick to a synthetic (e.g., plastic) substrate because when vibrated sufficiently to soften (make sticky) the coating and the substrate.
The conventional method for connecting the ends or end portions of the antenna wire to the terminals (or “terminal areas”) of the chip module is by means of thermo compression (TC) bonding. This method makes use of heat by passing pulses of electric current through a thermode and simultaneously applying pressure to cause a diffusion process between the wire and the leadframe of the chip module.
FIGS. 1A and 1B illustrate an example of a prior art technique, such as is disclosed in U.S. Pat. No. 6,233,818 for mounting an antenna wire to an inlay substrate and connecting the antenna wire to a chip module installed in a recess in the inlay substrate.
An inlay sheet 100 is a large inlay substrate which may have a plurality of transponder areas (or sites), a one of which is shown in some detail. Typically, several transponders (or transponder sites) are fabricated on a single inlay sheet.
A recess 106 is formed in the inlay substrate 102 for receiving a leadframe type RFID chip module 108, positioned as shown, with the mold mass 112 situated below a leadframe 114. The recess 106 is illustrated as a pocket-type recess extending only partially through the inlay substrate 102, which is shown as a single layer substrate. The inlay substrate may comprise multi-layers, such as two layers as indicated by the dashed lines passing across the substrate. Compare FIG. 1F.
The leadframe 114 of the chip module 108 has two terminal areas 108a and 108b. An antenna wire 110 having two connection portions (ends or end portions) 110a and 110b is mounted on or to the inlay substrate 102 and connected to the terminal areas 108a and 108b of the chip module 108.
The antenna wire 110 may be mounted to the substrate using an ultrasonic embedding tool such as a sonotrode having a capillary 116. Mounting the antenna wire 110 may proceed as follows:                using the sonotrode, embed the wire a short distance, between the points “a” and “b” near a first terminal of the chip module. (embedding is indicated by the symbols “x”)        stop embedding (raise the sonotrode), and pass over the first terminal 108a of the chip module 108, between the points “b” and “c”.        lower the sonotrode and resume embedding at the point “c”, and form the turns of the antenna between the points “c” and “d” (embedding is indicated by the symbols “x”)                    there may be for example 4 or 5 turns, and the overall length of the antenna wire may be 104 cm            notice that in forming the turns of the antenna, the wire may need to cross over itself, thus requiring an insulated wire. However, in some cases, the antenna wire does not need to cross over itself. See, for example, FIG. 4 of U.S. Pat. No. 6,698,089.                        after approaching near the second terminal 108b of the chip module 108, stop embedding and pass over the second terminal of the chip module, between the points “d” and “e”.        resume embedding a short distance on the opposite side of the chip module, between the points “e” and “f”.        
The embedding process (between the points “c” and “d”) may be discontinuous, at several points, rather than continuous.
In a next stage of the process, the “connection” portions of the wire passing over the terminal areas 108a and 108b are interconnected to the terminal areas of the chip module, typically by means of thermo compression bonding. (A first connection portion between the points “b” and “c” passes over the terminal 108a. A second connection portion between the points “d” and “e” passes over the terminal 108b.) A thermode 118 for performing bonding of the connection portions to the corresponding terminals is illustrated. It is known to remove insulation from the connection portions of the antenna wire to improve bonding.
In the case of an inlay substrate comprising Teslin™ (a synthetic paper), a normal insulated wire would not properly embed into the material, it would detach. Therefore, it is known to use self-bonding wire which attaches to the material with a slight penetration of the wire in the material.
A self-bonding (or self-adhering) wire may comprise                a metallic core (typically, but not necessarily round in cross-section) comprising copper, aluminum, doped copper, gold, or Litz wire, and may have a diameter of 0.010-0.50 mm        a first coating or “base coat” comprising modified polyurethane, and having a thickness of only a few microns        a second coating comprising polyvinylbutyral or polyamide, and having a thickness of only a few microns.        
The transponder thus formed on the inlay substrate may be incorporated, for example, in an electronic passport cover, as described hereinbelow.
Some Examples of Chip Modules
In the main hereinafter, the discussion may focus on RFID chip modules which are leadframe-type modules. However, some of the techniques for producing security documents discussed herein may also be applicable to epoxy glass modules (chip on FR4, wire bonded, glob topped).
FIG. 1C shows an example of an RFID chip module which is a “leadframe module” comprising:                a leadframe having a thickness of approximately 80 μm        an RFID chip disposed on and connected by wire bonds to the leadframe, having a thickness of approximately 80 μm        a mold mass disposed over the chip and wire bonds, having a thickness of approximately 240 μm        an antenna wire having end portions connected to “connection areas” of the leadframe, typically on a side of the leadframe opposite the RFID chip (as shown), but the end portions can also be connected to connection areas on the same side of the lead frame as the RFID chip.        
The total thickness of the leadframe module may be 320 μm, such as for an inlay substrate having a thickness of approximately 356 μm. Generally, the chip module will be disposed in a recess in the inlay substrate so as to be concealed therein.
FIG. 1D shows an example of an RFID chip module which is an “epoxy glass module” comprising:                an interconnect substrate, such as FR4 (printed circuit board substrate material), having a thickness of approximately 100 μm (FR4 is 100 μm and the chip & glob top 160 μm=overall 260 μm)        an RFID chip, wire-bonded (alternatively flip-chip connected with solder bumps and underfiller, as illustrated) to the FR4 substrate, having a thickness of approximately 100 μm        a glob top epoxy disposed over the chip and connections, having a thickness with chip of approximately 160 μm        an antenna wire having ends connected to “connection pads”, typically on the same side of the FR4 substrate as the RFID chip, but can also be connected on the opposite side of the FR4 substrate as the chip.        
The total thickness of the epoxy glass module may be 260 μm, such as for an inlay substrate having a thickness of approximately 365 μm. Generally, the chip module will be disposed in a recess in the inlay substrate so as to be concealed therein.
Generally speaking, epoxy glass modules are inherently somewhat more flexible than leadframe modules. This is a factor that may need to be taken into consideration when incorporating an RFID module into a secure document. And, whereas leadframe modules are typically rectangular, the mold part (glob top) of an epoxy glass module are typically round.
It should be understood that, although FIG. 1D shows a flip chip connection between the RFID chip and the FR4 substrate, the chip can be wire-bonded to the substrate (such as shown in FIG. 1C, for the leadframe-type module.)
Portions of the Antenna Wire
FIG. 1E shows a flat coil antenna structure having several (such as four or five turns) which may be formed of wire, such as self-bonding wire, and various portions of the resulting antenna structure, such as:                two ends which are generally the geometric “ends” of the elongate antenna wire        two end segments which are generally short portions of the antenna wire at each end of the antenna wire. The end segments include the ends, and may be connected to the terminals of the chip module, such as in U.S. Pat. No. 6,088,230 or US 2010/0141453.        two end portions which are also short portions of the antenna wire (exclusive of the ends or end segments) which may be connected to the terminals of the chip module, such as in U.S. Pat. No. 6,233,818 or U.S. Pat. No. 7,546,671.        a main or intermediate portion which is the longest portion of the antenna wire, between the two end portions, and which may be formed into several turns of a flat coil antenna (the intermediate portion may be referred to as the “main body portion” of the antenna wire)        
The “connection portions” of the antenna wire may be the ends (typically including end segments) or end portions (typically excluding end segments). In some embodiments, reference is made to “termination ends” of the antenna, which may mean substantially the same thing as “connection portions”.
Some Examples of “Final Products”
Transponders such as are shown in FIGS. 1A and 1B may be considered to be “interim products” in that some further steps or elements may be needed before getting the product into the “hands of the consumer”. For example, various cover layers may be laminated to the inlay substrate to protect (and secure) the transponder, as well as for imprinting with information. The end result, or “final product”, may be a secure document such as an electronic passport booklet or a smart card.
FIG. 1F shows an example of a security document which may be a National ID (identification) Card (or electronic ID, “eID” card) comprising a multi-layer (2 layer) inlay substrate, and additional layers comprising a top overlay layer and a bottom overlay layer. An RFID chip module and corresponding antenna (not shown) may be mounted in the inlay substrate(s). The chip module (not shown) may have a mold mass and a leadframe. The additional top and bottom layers may be anti-scratch layers, and protect the inlay substrate(s). The eID card, inlay substrate layer and top and bottom layers are not shown to scale.
Some dimensions for and properties of the layers may be:
Top overlay layertransparent80 micronsInlay substrate moldwhite185 microns Inlay Substrate - Leadtransparent80 micronsBottom Overlay Layertransparent80 microns
The layers of the inlay substrate for a smart card may comprise PVC, which has limited life. Smart cards are often replaced (renewed) every few years.
The layers of the inlay substrate for a national ID care may comprise PC (polycarbonate), which may be more durable (longer life) than PVC (polyvinyl chloride).
FIGS. 1G, 1H, 1I illustrate an exemplary construction for an electronic passport cover, corresponding generally to the single layer inlay substrate construction shown in FIG. 1B. The inlay substrate for a US passport may comprise Teslin™.
A cover layer may be disposed over the inlay substrate for the final product. The material for the cover layer may be a cloth product, with chemistry in the coatings and a leather-like appearance to the cloth, such as by Holliston Inc. (905 Holliston Mills Road, Church Hill, Tenn. 37642; www.holliston.com)
The cover layer may be laminated (joined) to the inlay substrate using a polyurethane hot melt adhesive, such as approximately 50-80 μm thick. Prior to the adhesive process, the inlay substrate may be pre-pressed to ensure that the antenna wire does not protrude over (extend above) the surface of the Teslin™ substrate, in other words, to ensure that the antenna wire is fully embedded in the inlay substrate.
With reference to FIG. 1H, in variations of the construction shown for an electronic passport cover (a similar secure document), the inlay substrate may be multi-layer, and if the recess extends completely through the inlay substrate, an underlying bottom layer may be provided to support the chip module.
Some dimensions for and properties of the layers of a passport cover may be:
cover layercloth350 micronsInlay substrateTeslin ™356 micronsMounting the Antenna to the Inlay Substrate
Various methods are known for mounting an antenna wire to the inlay substrate, and can generally be divided into two categories:                (i) “coil winding”, which comprises forming the antenna wire separately from the inlay substrate and installing the preformed antenna wire (sometimes with the chip module already mounted to ends of the antenna wire) thereto, and        (ii) “common substrate”, which comprises forming the antenna wire on the inlay substrate by scribing (typically ultrasonic embedding), and connecting ends or end portions of the antenna wire to terminal areas of the chip module        
Some of these techniques are described in the following patents and/or publications, all of which are incorporated by reference in their entirety herein.
U.S. Pat. No. 5,809,633 (Mundigl et al.), incorporated in its entirety by reference herein, discloses a method for producing a smart card module for contactless smart cards. As disclosed therein:                A method for producing a smart card module includes bonding one end of a thin wire onto a first contact zone of a semiconductor chip. The wire is guided in a plurality of turns forming an antenna coil. The wire is bonded onto a second contact area of the semiconductor chip. The wire turns of the antenna coil and the semiconductor chip are placed on a carrier body. (Abstract)        Referring now in detail to the single FIGURE of the drawing, there is seen a flat carrier body 1 which is made of flexible, non-conductive material and has a recess 2. A semiconductor chip 3 is inserted into the recess. The semiconductor chip 3 has two contact zones 4 which are enlarged in comparison with the customary chip contact zones through the use of a gold plating, for example. Connections 6 of an antenna coil 5 are secured on the contact zones 4 through the use of bond contacts. The antenna coil 5 is a wire which is advantageously made of aluminum. In this case, the wire has initially been bonded onto one of the contact zones 4, then wound through the use of a guiding head of an automatic wire-winding machine, into which a bonding device is integrated, in a plurality of turns to form the coil (only two turns are illustrated in the FIGURE, but there may also be more) and finally bonded again onto the other contact zone. The semiconductor chip 3 with the coil 5 which is secured thereto in an inventive manner is subsequently inserted into the recess 2 in the carrier body 1, with the result that the coil 5 is disposed on the carrier body 1. (column 2, lines 35-54)        
A known method of transferring a wire antenna onto or into a substrate is first to wind a coil on a mechanical fixture which includes a mechanism to hold an RFID chip in position, and through rotation of the tool a coil is formed with its wire ends positioned over the terminal areas of the chip (or chip module) for interconnection. For example, See EP 0 839 360, incorporated by reference herein. The antenna wire can be self-bonding wire which, when heated during the rotation of the coil winding tool, would form an antenna in which the turns of wire may be adhesively attached to one another.
U.S. Pat. No. 6,295,720 (Finn et al.), incorporated in its entirety by reference herein, describes a procedure of forming an antenna in a radial coil winding tool and mounting a chip in the tool before winding so as to arrange the wire ends of the coil over the terminal areas of the chip and then connecting the wire ends of the coil to the chip before placing the transponder (coil and connected chip) onto a substrate. See also EP 0 922 289, WO98/09305, PCT/DE97/017712).
EP 0 839 360 (Finn et al.), Verfahren and Vorrichtung zur Herstellung eines IC-Kartenmoduls, incorporated in its entirety by reference herein, discloses another coil winding technique. See also WO97/04415 (PCT/DE96/01121).
EP 1 352 551 (Michalk), incorporated in its entirety by reference herein, describes a procedure for fitting conductor wires on or in a substrate, with a conductor wire arrangement created outside the substrate before subsequently pressing the wire arrangement into said substrate, by first applying a pattern of conductor wire on a tensioning frame with the conductor wire being tightened in parallel or almost in parallel to the pressing plane of the tensioning frame via tensioning elements having a predefined pattern, and the conductor wire pattern being subsequently pressed and fixed in or on the substrate characterized in that during the pressing of the conductor wire pattern into the substrate, the tensioning elements slide back according to the pressing movement and release the conductor wire pattern, and in that the axially movable tensioning elements are pushed forward one after the other according to the conductor wire arrangement to be created from the pressing plane one after the other starting from the inside part of the conductor wire arrangement, thus creating the conductor wire pattern arrangement by a winding process.
To interconnect the wire ends of the wound coil to an RFID chip, the above procedure proposes that the electronic component be contacted on the tensioning frame with the conductor wire ends, and be pressed into the substrate together with the coil.
The procedure of forming a wire antenna or transponder unit using a coil winding process and then pressing the coil into a substrate by means of heat and pressure is highly unreliable, slow and difficult to automate for volume production. The tooling is also subject to wear and tear resulting in coils having different geometrical dimensions. One major disadvantage of this technique is the inability to form an antenna with a large pitch between the wire conductors which form the antenna.
U.S. Pat. No. 6,088,230, incorporated in its entirety by reference herein, overcomes some of the technical issues associated in using the technique of coil winding to produce a transponder site on a substrate. It describes a method of arranging a transponder site comprising at least one chip and one wire coil on a substrate, in particular a substrate used to produce a chip card, in which the chip and the wire coil are disposed on a common substrate and the coil wire ends are bonded to terminal areas of the chip on the substrate characterized in that the coil is formed by laying a coil wire in a wiring plane on the substrate, with the coil wire being bonded to the substrate at least at some points. See also EP 0 753 180
This technique of laying a wire onto or into a substrate and forming an antenna for connection to an RFID chip in producing a transponder site is known as “wire embedding”, and comprises using ultrasonic energy (delivered by a sonotrode) to stick the wire to or countersink the wire partially or entirely into a synthetic substrate (the inlay substrate).
Further examples of the common substrate technique can be found in U.S. Pat. No. 6,233,818 (Finn et al.) and subsequent U.S. Pat. No. 6,698,089 (Finn et al.), both of which are, incorporated in its entirety by reference herein. Generally, as disclosed therein,                Process and device for the contacting of a wire conductor (113) in the course of the manufacture of a transponder unit arranged on a substrate (111) and comprising a wire coil (112) and a chip unit (115), wherein in a first phase the wire conductor (113) is guided away via the terminal area (118, 119) or a region accepting the terminal area and is fixed on the substrate (111) relative to the terminal area (118, 119) or the region assigned to the terminal area, and in a second phase the connection of the wire conductor (113) to the terminal area (118,119) is effected by means of a connecting instrument (125). (Abstract, '818)        U.S. Pat. No. 6,233,818 discloses a conventional technique for mounting and connecting an antenna wire. FIGS. 4 and 5 of this patent show that a first end of the antenna wire starts on the substrate, passes over a first chip terminal, then continues on the substrate to form the (4 or 5) turns of the antenna, then passes over the second chip terminal, then terminates on the substrate.        U.S. Pat. No. 6,088,230 discloses a procedure for producing a transponder unit (55) provided with at least one chip (16) and one coil (18), and in particular a chip card/chip-mounting board (17) wherein the chip and the coil are mounted on one common substrate (15) and the coil is formed by installing a coil wire (21) and connecting the coil-wire ends (19, 23) to the contact surfaces (20, 24) of the chip on the substrate.        
A wire embedding technique may be found in U.S. Pat. No. 6,626,364 (Taban), incorporated in its entirety by reference herein.
Although these common substrate techniques represent a significant improvement over coil winding in terms of antenna quality and throughput, they have the disadvantage that different inlay formats (such as the pattern of the antenna coil) require significant mechanical alterations to the production equipment resulting in downtime and inefficient use of the equipment, in particular where the number of transponder sites on a format is very low, as is the case in the production of inlays for electronic passports (“2up” or “3up” formats).
U.S. Pat. No. 7,229,022 (Rietzler), incorporated in its entirety by reference herein, discloses method for producing a contactless chip card and chip card produced according to said method. As disclosed therein:                The invention relates to a method for producing a transponder, especially a contactless chip card (1) comprising at least one electronic component (chip module 2) and at least one antenna (3); the at least one electronic chip component (2) being disposed on a non-conducting substrate that serves as a support for the component. The at least one antenna is also disposed on a non-conducting substrate, the at least one electronic component (2) being applied to a first substrate and the antenna (3) on a second substrate. The entire circuit (1) is then produced by joining the individual substrates so that they are correctly positioned relative to each other. The components (2, 3) are contacted once the different substrates have been joint by means of auxiliary materials such as solder or glue, or without auxiliary materials by microwelding. The non-conducting substrates form a base card body. (Abstract)        FIG. 3 shows the individual substrate before the assembly in the use arrangement. Substrate 11 supports the antenna 12, whereby this is arranged exactly in the defined use arrangement and position. On the antenna substrate, assistance lines 13 can be applied, which simplify the orientation on one another of both substrates. The antennae 12 lie on the underside of the substrates, that is, on the side facing toward the second substrate. The second substrate 14 shows the substrate on which the chip modules 15 already are mounted. The chip modules are already fixed onto the substrate by means of the previously described method. The chip modules 15 lie on the top side, that is, on the side of the substrate facing the antennae 12.        For further processing, both substrates 11 and 14 are oriented to be correctly position and pressed onto one another.        FIG. 4 shows the view of the joined substrates of a transponder in cross section. One recognizes the lower substrate 16 on which the chip module 17 is arranged. Opposite is the upper substrate 20, which supports the antenna 19 on its underside. In the contact region 18, the antenna 19 and the contact surfaces 23 of the chip module overlap. At this point, the electrical connection is formed.        In this view, additionally an equalizing substrate 21 is shown. This substrate does not support any components, rather contains only an opening 22, in which the chip module 17 comes to rest after the assembly process. (column 5, lines 11-37)        
US 2008/0314990 (Rietzler), incorporated in its entirety by reference herein, discloses chip card and method for the production of a chip card. See also WO07/065,404. As disclosed therein,                The invention pertains to a chip card and to a method for producing a chip card with a chip module that is contacted with an external contact arrangement arranged in the contact surface of a card body, as well as with an antenna device arranged in a card inlay, wherein the card inlay is initially produced in a first production device and the card inlay is subsequently provided with at least one respective external layer on both sides in a second production device, namely in such a way that the external contact arrangement arranged on the external contact side of the chip carrier is introduced into a recess of the assigned external layer, and wherein a connection between the card inlay and the external layers is subsequently produced in a laminating process. (Abstract)        FIG. 1 shows an arrangement of a plurality of so-called panel sheets that respectively feature a plurality of layers interconnected in one piece in the form of a panel arrangement in order to produce a card inlay sheet 10 according to FIG. 5 with a plurality of interconnected card inlays 11. FIG. 1 specifically shows a receptacle layer sheet 12 with a plurality of interconnected receptacle layers 13 and a cover layer sheet 14 with a plurality of interconnected cover layers 15.        The receptacle layer sheet 12 and the cover layer sheet 14 are situated between a lower laminator plate 17 and an upper laminator plate 18 of a laminator arrangement 16. The lower laminator plate 17 is provided with an arrangement 19 of recesses 20 corresponding to the panel arrangement of the receptacle layer sheet 12 and serving for accommodating a corresponding number of chip modules 21.        The receptacle layers 13 of the receptacle layer sheet 12 respectively serve as antenna substrates, on which one respective antenna device 22 with several antenna windings 23 is arranged, namely in the form of a wire arrangement in the example shown. The antenna devices 22 respectively feature two contact ends 24, 25 that extend over contacting bays 26 in an opening edge 27 of a recess 28.        The receptacle layer sheet 12, as well as the cover layer sheet 14, consists of a plastic material that can be laminated such as, for example, polyethylene or PVC.        
The Rietzler references (U.S. Pat. No. 7,229,022 and US 2008/0314990) may be considered to be a “modified” form of coil winding in that antenna structures are formed on a substrate other than the inlay (chip module containing) substrate.
In the teachings of U.S. Pat. No. 7,229,022 and US 2008/0314990 an array of antennae are installed on a separate substrate to the substrate hosting the RFID chips with an identical format. The antenna substrate is then placed over the substrate with the array of RFID chips and the termination areas of each antenna are manually connected to each chip on the respective transponder site. It is worth noting that the wire ends of each antenna span a bridge over an opening in the antenna substrate and therefore a distance remains between the wire bridges over the opening and the chip modules on the other substrate. A difficulty with such a method is alignment of the wire ends with the terminal areas of a chip module, which may require manually aligning the wire ends for interconnection by hand.